Re: [PATCH v2] thunderbolt: debugfs: Don't stop reading SB registers if just one fails

[Mika Westerberg]

On Mon, Apr 13, 2026 at 11:02:43AM +0200, Konrad Dybcio wrote:
> From: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
> 
> The GEN4 TxFFE register is not part of the USB4 v1.0 specification, so
> understandably some pre-USB4v2 retimers (like the Parade PS8830) don't
> seem to implement it.
> 
> The immediate idea to counter this would be to introduce a version
> check for that specific register, but on a second thought, the current
> flow only returns a quiet -EIO if there's any failures, without hinting
> at what the actual problem is.
> 
> To take care of both of these issues, simply print an error line for
> each SB register read that fails and go on with attempting to read the
> others.
> 
> Note that this is not quite in-spec behavior ("The SB Register Space
> registers shall have the structure and fields described in Table 4-17.
> Registers not listed in Table 4-20 are undefined and shall not be
> used."), but it's the easiest fix that shouldn't have real-world bad
> side effects.
> 
> Fixes: 6d241fa00159 ("thunderbolt: Add sideband register access to debugfs")
> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>

Applied to thunderbolt.git/next, thanks!